The present invention relates to a durable, multi-layer polymeric, stretch resistant flexible pouch (bag) having heat sealingly laminated side margines and a rigidly brimmed wide mouth open end. This pouch is particularly useful for sealed containment and storage of liquids, solids, granulates and powders such as those commonly stored in other types of containers, e.g., jars, bottles, and cans. Use of this rigid mouth pouch will contribute greatly to source reduction of plastic waste in that this pouch can serve as a prefilled refill that can be conveniently inserted into reusable dispensing bottles, and by repeatedly replacing emptied prefilled refills a dispensing bottle can be reused numerous times. Also, this pouch can serve as a basic stand up container having substantially less disposable plastic than bottles.
More particularly the present invention relates to a high strength plastic pouch having an open end portion that is forcefully stretched onto an annular rim, wherein the open end portion tightly engages the rim, so as to provide the pouch with a rigid brim that facilitates filling and sealing closure of the pouch using equipment and methods that are commonly used for filling and sealing closure of bottles. Filled or empty the brimmed pouch is capable of withstanding aggressive handling, shipping and storage, and during filling and closure operations the brim facilitates temporary support of the pouch in a carrier. In addition, the brimmed end of the pouch facilitates standing of filled and closed pouches on store shelves. The brimmed end also facilitates use of the pouch in squeeze bottle, pump dispenser and other dispensing bottle applications.
In applicant's above mentioned related inventions the inside surface at the open end of a flaccid bag is merely shown to be bonded to the outer vertical wall surface of a fitment ring, or vice versa. Either way, attachment of the bag to the fitment ring is difficult to achieve. A practicable process for such attachment has not yet been devised. In addition, attachment to the vertical wall produces an undesirable product entrapment region, that causes an undesireable amount of product to remain in the bag, because the bag is not free to displace product in the entrapment region.
The present invention distinguishes over applicant's mentioned related inventions, in that, it defines a novel stretch resistant pouch being secured to a substantially rigid annular rim, by an open end of the pouch being mechanically expanded and tightly contracted over, around and beneath the rim. The product entrapment region discussed above, in reference to applicant's related inventions, is eliminated in the present invention. Thus, the present invention defines an improved pouch having a substantially smooth and unwrinkled rigid brimmed fill opening.
The need for a plastic bag being attached to a ring, so as to produce a high strength plastic pouch having a rigid open mouth, has existed for many years. Many ideas have been explored in attempts to provide an economical method of producing such pouch have been tried without too much success. This is evidenced by applicant's above mentioned related inventions as well as U.S. Pat. No. 3,420,413 issued to D. F. Corsette on Jan. 7, 1969 and U.S. Pat. No. 4,147,278 issued to Albert Uhlig on Apr. 3, 1979.
The Corsette patent typifies one approach by providing a costly pouch having a molded in place neck so as to overcome problems associated with supporting the pouch within an outer container and sealing.
Using a different approach, the Uhlig patent provides an inexpensive flaccid bag that is simply cuffed back over the neck of a bottle. Uhlig defines an easily stretchable flexible plastic film bag, which is separated along perforations from a roll of such bags. It is essentially a disposable baby bottle bag. The Uhlig concept requires the bag to be in place during filling, and Uhlig does not account for excessive leak path wrinkles that are produced at the sealing surface. Also, the bag must be attached to a bottle, it cannot be used alone, it lacks strength and durability. Experence has shown that the Uhlig bag is prone to the development of leaks at its corners.
It is also pointed out that well known easily stretchable polyethylene pouches, such as those having an open end that is folded over the opening of a baby bottle, have a pair of tear-off flaps which are provided for pulling the open end of the pouch over the mouth of the bottle. Also, to facilitate pulling the pouch, without tearing the flaps off, the pouch must be sized such that the outer surface circumference of the pouch is approximately equal to the outer surface circumference of the bottle opening. Thus, when the pouch end is folded over it is not tightly contracted into place and the portion of the pouch that overlies the bottle opening is prone to slipping loose. As a result the flaps are also necessary aids that prevent the pouch from slipping off of the bottle while the pouch is being filled. This method of holding a pouch in a baby bottle is only suitable for momentary support of a filled pouch while a retainment cap is tightened into place.
The baby bottle pouch tear-off flaps are useless for a reinforced stretch resistant pouch because they tear away under the force required to stretch the pouch over a flange. Even if the flaps are not made to tear off, stretch resistant bags having pull flaps have been tested and found to be unfit for stretching onto an annular rim because they do not distribute the pull force uniformly. As a result the pouch is overly stressed and unusably deformed.
The only method found to be suitable, for stretching the open end of a pouch onto a rim, is by use of an expanding apparatus, as will be described hereinafter in substantial detail, having collet sectors that facilitate controlled uniform stretching and release of the pouch.